Common law courts are bound by authoritative precedent. This principle — stare decisis — is fundamental for guaranteeing certainty in the law. Subject to extraordinary exceptions, a lower court must apply the decisions of higher courts to the facts before it. This is called vertical stare decisis. [FN]
R. v. Comeau,  1 SCR 342, 2018 SCC 15 (CanLII), at para. 26.
However, stare decisis is not a straitjacket that condemns the law to stasis. Trial courts may reconsider settled rulings of higher courts in two situations:
(1) where a new legal issue is raised; and
(2) where there is a change in the circumstances or evidence that “fundamentally shifts the parameters of the debate”
Canada (Attorney General) v. Bedford, 2018 SCC 72 (CanLII), at para. 42.
While the latter exception is a narrow one [FN], it has been found to have been engaged where the underlying social context that framed the original legal debate is profoundly altered.
See Carter v. Canada (Attorney General), 2015 SCC 5 (CanLII), at para. 44.
Of course, lower courts have the right to make a distinction based on the background facts before them. But for a binding precedent from a higher court to be cast aside on the basis of new evidence, the new evidence must “fundamentally shift” how jurists understand the legal question at issue. It is not enough that the new evidence supports an alternative interpretation of the law.
See R. v. Comeau,  1 SCR 342, 2018 SCC 15 (CanLII).
Written by Stuart O’Connell, O’Connell Law Group
[FN] Bedford, at para. 44; Carter v. Canada (Attorney General), at para. 44.